You aren't being oversensitive at all, in my opinion. It sounds like your mother is controlling and even being a bully at times. Can you stay busy with friends and out of the house activities to minimize contact while you are home for break?

Others may have more constructive advice. My mom was controlling, too. It was very hard for me to stand up to her. My brother was like yours and ignored her. I had trouble doing that. *hugs*